Search results for "Operations"
showing 10 items of 1692 documents
Comparative evaluation of the effect of the substrate thickness and inherent process defects on the static and fatigue performance of FSW and adhesiv…
2021
Abstract This work aims at evaluating the mechanical performance of joints in an AA6016 alloy, manufactured by means of two alternative processes: friction stir welding and adhesive bonding. Given its wide use in industrial fields such as automotive and aeronautics, an overlap configuration of joints was selected for the study, and a specific method based on the overlap length evaluation has been developed to allow comparisons among the cases. Two substrate thicknesses are considered in order to vary the overall joint stiffness, and the effect of such geometrical parameter on the mechanical behavior of the joined system is experimentally investigated. The experimental findings highlight tha…
Experiments of Reduced Working Hours in Finnish Municipalities
1999
This article examines experiments with shorter working hours in Finnish municipalities between 1996 and 1998. The article focuses on the effects of different working time experiments on employees (work ability), on working units (quality of services) and substitutes recruited during the experiments. The results indicate that shorter working hours reduce job exhaustion, with respect to both 6‐hour shifts and other forms of reduced hours. The participants reported positive changes the quality and availability of services, especially in the case of 6‐hour shifts. In addition, during the experiment, new employees (substitutes) reported improved chances to obtain work in the future; after the ex…
Spatial fragmentation of, and US support for, the main multilateral institutions of the western order
2017
The growth of China-led minilateral initiatives mostly of a regional character has challenged the main multilateral institutions of the Western order and, ultimately, US authority. Faced with a progressive delegitimation of the institutional architecture that it promoted after World War II, the US, under the Obama administration, has acted to defend the existing main multilateral institutions of the order (UN, IMF, WB and WTO), attributing them with a strategic role. More than being radical, though, the reforms enacted have been incremental and pragmatic, but always imperfect. More importantly, they have not altered US influence, which is exercised mostly through informal means. This, howev…
Management and interaction with multimodal information content
2010
[Chbeir, Richard] Univ Bourgogne, CNRS, LE2I, Dept Comp Sci, F-21000 Dijon, France. [Coninx, Karin] Univ Hasselt, Expertise Ctr Digital Media EDM, BE-3590 Diepenbeek, Belgium. [Ferri, Fernando; Grifoni, Patrizia] CNR, Inst Res Populat & Social Policies, Rome, Italy.
Quasi order, pseudo order and not order
1995
This study, after having presented the structure of total semi-order and that of pseudo-order one, presents a new preference structure called non order. This one generalizes both the semi-order structure and the pseudo-order one. The details analysis are based on the usual concepts of the relationnal approach of preference modelling and on some new concepts and principles which fit the imprecise context. These new principles are : imprecise discriminant power, imprecise transitivity, imprecise intransitivity and generalized limited comparability. The new concepts are : preference relationnal constituent and preference relationnal state.
Distribution of power and social utility under nonadditive aggregation rules
1992
In this paper, we try first to shift the problem onto the agents. We want actually to consider some methods for passing from coalitions to lotteries over coalitions. These methods are associated with a function that could correspond to a social utility function. It gives the level of satisfaction coming from the anticipated "consumption" of a subset of alternatives (goods, candidates,..) by a coalition. Second, we want to define the distributions of power regardless of those two-element feasible sets which characterize preferences in basic models on one side, and we try to exhibit a theoretical relation between the basic Barberà & Sonnenschein’s model and ours thanks to the Choice Axiom of …
De l'effet d'imprécision et du paradoxe de la non ponctualité des seuils vers la définition de quelques concepts et principes de modélisation des pré…
1994
(EN) This survey deals with conceptual and theoritical basis of imprecise preference modelling. From the establishment of non-punctuality of the imprecise preference threshold, imprecise discrimination power is set. This involves that the modelling preference relation tool is composite. Which allows a generalization of the limited comparability principle and an introduction of new concepts which adapt to this theoritical framework.(FR) Ce travail pose les fondements conceptuels et théoriques de la modélisation des préférences imprécises. A partir du constat de non ponctualité des seuils de préférence, il pose le principe du pouvoir discriminant imprécis. Il en résulte que l'outil relationne…
Théorie de système et séries temporelles
1994
The aim of this paper is to present a different representation of state space models, (innovation state space representation) which is relatively new and apparently unknown in the economics and econometrics literature and to describe some of its properties. state space representation is a very flexible form for time series and the approach taken in this paper therefore allows a broad class of models it does not impose a priori the decomposition of data series into trend and cycle
Continuous optimal control sensitivity analysis with AD
2000
In order to apply a parametric method to a minimum time control problem in celestial mechanics, a sensitivity analysis is performed. The analysis is continuous in the sense that it is done in the infinite dimensional control setting. The resulting sufficient second order condition is evaluated by means of automatic differentiation, while the associated sensitivity derivative is computed by continuous reverse differentiation. The numerical results are given for several examples of orbit transfer, also illustrating the advantages of automatic differentiation over finite differences for the computation of gradients on the discretized problem.
Sensitivity analysis for time optimal orbit transfer
2001
The minimum time transfer of a satellite around the Earth is studied. In order to deal numerically with low thrusts, a new method is introduced: Based on a so-called noncontrollability function, the technique treats the ha1 time as a parameter. The properties of the method arc studied by means of an infinite dimensional sensitivity analysis. The numerical results obtained by this approach for very low thrusts are given